The Ministry of Defence has refused to say whether American nuclear weapons are set to return to British soil, following a 14-year absence.
US government budget documents revealed earlier this month that vaults at RAF Lakenheath near Cambridge are being upgraded with the ability to store B61-12 nuclear bombs.
During the Cold War the US maintained a stockpile of nukes in Britain, with the last weapon going home in 2008 after relations with Russia thawed.
But the changes at the base have prompted concerns among MPs that the government may again allow the US military to store land-based nuclear weapons 20 miles from Cambridge, with no discussion or debate.
"The MoD is unable to comment on US spending decisions and capabilities, which are a matter for the US government," defence minister James Heappey said in a written parliamentary answer about the upgrade of the vaults at the base.
"It remains longstanding UK and Nato policy to neither confirm nor deny the presence of nuclear weapons at a given location."
The Independent approached the Ministry of Defence on Tuesday to ask whether there would be any notification in the event US nuclear weapons returned to British soil, and was told again that it was policy to neither confirm nor deny the presence of such weapons.
Green MP Caroline Lucas said it was "deeply irresponsible" for the government to keep the public in the dark on the issue and for any change to go through without scrutiny.
“We are at a nuclear crisis point not seen since the Cuban Missile Crisis. Lowering the nuclear danger right now is vital," she told The Independent.
"If Nato members are not only continuing to renege on their agreed responsibilities under the Nuclear Non-Proliferation Treaty to wind down nuclear weapons, but are in fact reinforcing their nuclear capacity, then the public must be informed, and an honest discussion must be had about its implications.
"It’s deeply irresponsible for the Ministry of Defence to keep the public in the dark about these decisions of global significance, and dodge any accountability for nuclear weapons being maintained and upgraded on our own shores. It’s time for the Government to open up and come clean.”
RAF Lakenheath has been the site of numerous protests against nuclear weapons and US military action, and subject to claims that its presence endangers nearby Cambridge.
The Suffolk airbase was previously used by the US military to stockpile stockpile nuclear bombs, but its vaults were mothballed after the weapons were withdrawn in 2008. Two accidents involving nuclear weapons took place at the base in 1956 and 1961.
In the 1990s RAF Lakenheath had 33 underground storage vaults, where 110 bombs were stored, according to the nuclear information project at the Federation of American Scientists, which first reported the budget document.
The UK's own nuclear arsenal, Trident, is mostly submarine-based, with weapons also handled at the Faslane naval base on the Clyde in Scotland.
Hans Kristensen, the information project's director, said earlier this month that it was "unclear if nuclear weapons have been returned to the base yet or NATO is upgrading the base to be capable of receiving nuclear weapons in the future if necessary".
FAS estimates there currently are roughly 100 nuclear bombs deployed at six air bases in five European countries.
The upgrades at the base were revealed in the Biden administration’s 2023 defence budget request, which for the first time included the UK is a list of countries where “special weapons” storage sites are being upgraded.
Britain is now listed alongside Belgium, Germany, Italy, the Netherlands and Turkey in this section of the military construction programme – all countries where the US stores stockpiles of B61 nuclear bombs. The so-called "gravity bombs" are dropped from aircraft rather than launched in a missile.
Daryl Kimball, executive director of the Arms Control Association told The Independent: "The official 'will neither confirm nor deny the presence of nuclear weapons at a given location' response from the UK government is not surprising, but it is disappointing and undemocratic.
"US and UK citizens have a right to know whether there have been changes in national nuclear policies, and how their nations are collaborating on nuclear weapons deployments, and whether their communities may become targets in a nuclear attack because they are storage sites for nuclear weapons.”
